Recently the digital cameras have become very common. These digital cameras have higher performance and they can undertake many functions. For example, digital cameras now can continuously record sounds.
However, there is a problem in the conventional digital cameras that a still image cannot be captured during recording of sounds. For example, when a still image of an object is to be captured while sound recording of a conference is going on, it is necessary to first stop the sound recording and then capture the image of the object. That is, it was impossible to perform sound recording and capturing a still image simultaneously.